Child-resistant blister package

ABSTRACT

An improved child-resistant blister package is provided in which the lidding component includes a tear-resistant nonwoven layer and a barrier layer. The nonwoven layer can be a melt-spun continuous filament nonwoven web or a flash spun plexifilamentary sheet. The lidding component used in peel off-push through blister packages of the invention contains fewer layers and has improved puncture resistance compared to lidding components used in child-resistant packages known in the art. In addition, in peel off-push through and peel-open package designs of the present invention, the lidding peels more cleanly from the blister component compared to packages known in the art which have a tendency to tear during peeling.

BACKGROUND OF THE INVENTION

The present invention relates to improved child-resistant blisterpackaging. More particularly, this invention relates to blisterpackaging that includes a lidding component that comprises at least onenonwoven layer selected from the group consisting of melt-spuncontinuous filament nonwoven sheets and flash spun plexifilamentarysheets.

Blister packages are known in the art, for example as packaging forpharmaceuticals and other materials. Blister packages include a blistercomponent having at least one cavity formed therein into which themedicine or other packaged material is placed prior to being sealed to alidding or top web component. Blister components known in the artinclude soft-tempered aluminum foils, hard-tempered aluminum foils,multi-layer cold formable foils, and thermoformed films. Liddingcomponents known in the art include films, and combinations of films,paper, and/or foil. The lidding component generally has a heat-seallayer applied to one side thereof which is used to heat seal the liddingcomponent to the blister component during the manufacture of the blisterpackage. When used for packaging pharmaceuticals and other materialsthat are oxygen- and/or moisture-sensitive, the blister package shouldhave sufficient barrier properties to ensure a reasonable shelf-life forthe packaged materials. When used for packaging pharmaceuticals or othermaterials that may be harmful to children, a blister package should alsobe child-resistant so that a child cannot open the package, bite throughit, or otherwise damage the packaging in a way that exposes the packagedpharmaceutical or other packaged material. At the same time, it isgenerally desirable that an adult can open the blister package withoutundue effort.

Examples of blister packages known in the art include peel-open,tear-open, push-through, and peel off-push through packages. In apeel-open package, the lidding component is peeled away from the blistercomponent to reveal the packaged material. In a tear-open package, thelidding and blister components contain a notch or perforation thatextends from an edge of the package in the direction of the cavity. Thenotch can be made in an external edge of a package, or, for packagescomprising multiple blisters separated by perforations, the notch ispreferably contained internal to the package such that when anindividual blister is separated at the perforations from the rest of theblisters in the package, the notch in the separated blister is on anexposed edge thereof. The package is then torn at the notch and the tearis propagated until the contents of the package are capable of beingremoved. In a push-through package, the packaged material is pushedthrough the lidding component by applying finger pressure to theexterior of the blister cavity. In a peel off-push through package, thelidding component is a multi-layer laminate that generally includes anouter paper layer bonded by an intermediate adhesive layer to a filmlayer (e.g. polyester film), with the film layer also being bonded by apeelable adhesive layer to a foil layer on the side of the film oppositethat which is bonded to the paper layer. The foil layer generally has aheat-seal layer coated or otherwise applied to the side of the foilopposite the film which provides a non-peelable seal when heat-sealed tothe blister component. To open the package, the lidding is peeledbetween the film and the foil layers, leaving the foil layer attached tothe blister component. After peeling off the combined paper and filmlidding layers, the packaged material is pushed through the liddinglayer(s) that remains attached to the blister component. Generally thepeelable adhesive layer remains adhered to the film layer during peelingsuch that only the foil layer remains attached to the blister componentafter peeling. An example of a peel off-push through blister package isdescribed in Brunda, U.S. Pat. No. 3,899,080. The blister packagecomprises a peelable outer layer, for example film, cardboard, or paperthat is adhered by a peelable adhesive to a rupturable layer such aspaper, selected plastics, or metal foil.

One challenge in the manufacture of blister packaging is to make apackage that is child resistant that can also be opened by an adultwithout undue difficulty. Certain child-resistant blister packages knownin the art include peel-open packages that comprise a laminatedpaper-film lidding component adhered to a plastic blister component by apeelable sealant. Further child-resistance is obtained using peeloff-push through packages, which comprise the multi-layer liddingmaterial described above. One disadvantage of current peel off-pushthrough packages is that paper-film-foil laminates used in the liddingdo not generally peel cleanly in one piece and often tear at theperforation, making it difficult to initiate a new peel. Some paper-filmlaminates and paper-film-foil laminates also have poor punctureresistance and can be chewed through by a child. Another disadvantage ofusing paper-film laminates or paper-film-foil laminates in the liddingcomponent is that it is not unusual to have problems with moisture beingsealed in the blister when moisture that is retained in the paper formssteam at the high temperatures used in the heat-sealing process.

Poore, British patent GB 2151581 describes push-through strip packagingdescribed as child-resistant that includes first and second planar sheetmaterials with the packaged elements enclosed therebetween. Neither ofthe planar sheet materials contains pre-formed blisters, but rather thenecessary accommodation of the packaged elements is afforded bystretching of the material of each sheet as they are sealed together.The first sheet is a laminate of a paper or a foil with a tear-resistantbiaxially oriented plastic material together with an adhesive layer thatis preferably a heat-sealable adhesive layer. The second sheetpreferably has a push through force of at least about 70 N and comprisesa laminate of paper or metal foil and a layer of plastic or othermaterial that can provide adhesive properties, preferably aheat-sealable adhesive. The package permits the removal of individualelements through the second sheet by application of finger pressure.

Gerber published European Patent Application 0959020 describes a peeloff-push through type blister package that includes a cover sheetcontaining a metal foil-free push-through penetrable plastic layer, apeelable release adhesive, and a non-penetrable cover layer. The coverlayer is peeled off the release adhesive in a first step and thepackaged material is pushed through the metal foil-free penetrableplastic layer. Suitable cover layers include mono-films, film laminatescontaining thermoplastics, papers or layered materials of thermoplasticpaper. Suitable papers include cellulose papers, security papers, andpapers made of synthetic fibers.

Carter, U.S. Pat. No. 4,947,620 describes a blister pack suitable forsteam sterilization that includes a lidding material of Tyvek® nonwovenmaterial that is coated with an adhesive only on the areas of thelidding that are bonded to the blister component. The Tyvek® nonwovenmaterial is breathable and therefore such packaging is not suitable forpackaging pharmaceuticals and other materials that are oxygen ormoisture sensitive.

There remains a need for improved child-resistant blister packaging thatprotects materials packaged therein from moisture and/or oxygen that isalso economical to manufacture.

BRIEF SUMMARY OF THE INVENTION

In a first embodiment, the present invention is directed to a blisterpackage comprising a blister component having an inner surface and anouter surface and a multi-layer lidding component having an innersurface and an outer surface, wherein selected portions of the innersurfaces of the blister and lidding components are adhered together toform at least one cavity therebetween, the blister component comprisinga first barrier layer selected from the group consisting of polymericfilms, coated polymeric films, metal foils, and film-foil laminates, andthe lidding component comprising a second barrier layer and a nonwovenlayer comprising at least one melt-spun continuous filament nonwovensheet.

A second embodiment of the present invention is a blister packagecomprising a blister component having an inner surface and an outersurface and a multi-layer lidding component having an inner surface andan outer surface, wherein selected portions of the inner surfaces of theblister and lidding components are bonded together to form at least onecavity therebetween, the blister component comprising a first barrierlayer selected from the group consisting of polymeric films, coatedpolymeric films, metal foils, and film-foil laminates, and the liddingcomponent comprising a flash spun plexifilamentary sheet and a secondbarrier layer comprising a sheet layer selected from the groupconsisting of polymeric films, coated polymeric films, and metalizedpolymeric films.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic elevation view of a blister package.

FIG. 2 a is a schematic cross-sectional view of a lidding materialuseful in blister packages of the present invention.

FIG. 2 b is a schematic cross-sectional view of a second embodiment of alidding material useful in blister packages of the present invention.

FIG. 3 is a schematic diagram of a process suitable for preparing ablister package of the present invention.

FIG. 4 is a portion of the product made by the process of FIG. 3,showing multiple blister packages.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an improved child-resistant blisterpackage that comprises a multi-layer lidding component and a blistercomponent. The multi-layer lidding component includes at least onebarrier layer and at least one nonwoven layer selected from the groupconsisting of melt-spun continuous filament nonwoven sheets and flashspun plexifilamentary sheets. The blister packages of the presentinvention include peel-open, tear-open, and peel off-push throughpackages. The use of a melt-spun continuous filament nonwoven sheet orflash spun plexifilamentary sheet in the lidding results in a blisterpackage that is difficult or impossible to open by pushing the packageditem through the lidding or by chewing through the lidding, thusimproving the degree of child resistance compared to packages known inthe art. The term “copolymer” as used herein includes random, block,alternating, and graft copolymers prepared by polymerizing two or morecomonomers and thus includes dipolymers, terpolymers, etc.

The term “polyethylene” (PE) as used herein is intended to encompass notonly homopolymers of ethylene, but also copolymers wherein at least 85%of the recurring units are ethylene units, and includes “linear lowdensity polyethylenes” (LLDPE) which are linear ethylene/α-olefincopolymers having a density of less than about 0.955 g/cm³, and “highdensity polyethylenes” (HDPE), which are polyethylene homopolymershaving a density of at least about 0.94 g/cm³.

The term “polyester” as used herein is intended to embrace polymerswherein at least 85% of the recurring units are condensation products ofdicarboxylic acids and dihydroxy alcohols with linkages created byformation of ester units. Examples of polyesters include poly(ethyleneterephthalate) (PET), which is a condensation product of ethylene glycoland terephthalic acid, and poly(1,3-propylene terephthalate), which is acondensation product of 1,3-propanediol and terephthalic acid.

The term “polyamide” as used herein is intended to embrace polymerscontaining recurring amide (—CONH—) groups. One class of polyamides isprepared by copolymerizing one or more dicarboxylic acids with one ormore diamines. Examples of polyamides suitable for use in the presentinvention include poly(hexamethylene adipamide) (nylon 6,6) andpolycaprolactam (nylon 6).

The term “barrier layer” as used herein refers to a sheet layer,including films and coatings that restrict the permeation of oxygenand/or water vapor into a blister package that comprises the sheetlayer. Barrier layers suitable for use in the present inventionpreferably have a moisture vapor transmission rate (MVTR) of less than 6g/m²/24 hr measured according to ASTM F 1249 under the conditions of 38°C. and 90% Relative Humidity and/or an oxygen transmission rate of lessthan 28 cm³/m²/24 hr measured according to ASTM D3985 under theconditions of 23° C., 100% oxygen, and 100% Relative Humidity.

The terms “nonwoven fabric”, “nonwoven sheet”, “nonwoven layer”, and“nonwoven web” as used herein refer to a structure of individual fibers,filaments, or threads that are positioned in a random manner to form aplanar material without an identifiable pattern, as opposed to a knittedor woven fabric. Examples of nonwoven fabrics include meltblown webs,spunbond nonwoven webs, flash spun webs, carded webs, spunlaced webs,and composite sheets comprising more than one nonwoven web.

The term “machine direction” (MD) is used herein to refer to thedirection in which a nonwoven web is produced (e.g. the direction oftravel of the supporting surface upon which the fibers are laid downduring formation of the nonwoven web). The term “cross direction” (XD)refers to the direction generally perpendicular to the machine directionin the plane of the web.

The term “spunbond fibers” as used herein means fibers that aremelt-spun by extruding molten thermoplastic polymer material as fibersfrom a plurality of fine, usually circular, capillaries of a spinneretwith the diameter of the extruded fibers then being rapidly reduced bydrawing and then quenching the fibers.

The term “meltblown fibers” as used herein, means fibers that aremelt-spun by meltblowing, which comprises extruding a melt-processablepolymer through a plurality of capillaries as molten streams into a highvelocity gas (e.g. air) stream.

The term “spunbond-meltblown-spunbond nonwoven fabric” (“SMS”) as usedherein refers to a multi-layer composite sheet comprising a web ofmeltblown fibers sandwiched between and bonded to two spunbond layers.Additional spunbond and/or meltblown layers can be incorporated in thecomposite sheet, for example spunbond-meltblown-meltblown-spunbond webs(“SMMS”), etc.

The term “multiple component fiber” as used herein refers to a fiberthat is composed of at least two distinct polymeric components that havebeen spun together to form a single fiber. The at least two polymericcomponents are arranged in distinct substantially constantly positionedzones across the cross-section of the multiple component fibers, thezones extending substantially continuously along the length of thefibers.

The term “bicomponent fiber” is used herein to refer to a multiplecomponent fiber that is made from two distinct polymer components, suchas sheath-core fibers that comprises a first polymeric component formingthe sheath, and a second polymeric component forming the core; andside-by-side fibers, in which the first polymeric component forms atleast one segment that is adjacent at least one segment formed of thesecond polymeric component, each segment being substantially continuousalong the length of the fiber with both polymeric components beingexposed on the fiber surface. Multiple component fibers aredistinguished from fibers that are extruded from a single homogeneous orheterogeneous blend of polymeric materials. The term “multiple componentnonwoven web” as used herein refers to a nonwoven web comprisingmultiple component fibers. The term “bicomponent web” as used hereinrefers to a nonwoven web comprising bicomponent fibers. A multiplecomponent web can comprise single component and/or polymer blend fibersin addition to multiple component fibers.

The term “plexifilamentary” as used herein, means a three-dimensionalintegral network or web of a multitude of thin, ribbon-like, film-fibrilelements of random length and with a mean film thickness of less thanabout 4 microns and a median fibril width of less than about 25 microns.In plexifilamentary structures, the film-fibril elements are generallycoextensively aligned with the longitudinal axis of the structure andthey intermittently unite and separate at irregular intervals in variousplaces throughout the length, width and thickness of the structure toform a continuous three-dimensional network. A nonwoven web ofplexifilamentary film-fibril elements is referred to herein as a “flashspun plexifilamentary sheet”. Conventional flash spinning processes forforming web layers of plexifilamentary film-fibril strand material aredisclosed in U.S. Pat. Nos. 3,081,519 (Blades et al.), 3,169,899(Steuber), 3,227,784 (Blades et al.), 3,851,023 (Brethauer et al.), thecontents of which are hereby incorporated by reference.

As used herein, the term “film” includes layers that are extrudeddirectly onto one of the other layers in the lidding or blistercomponents, as well as films that are formed in a separate film-formingstep and then laminated to one or more other layers.

The term “full-surface bonded nonwoven fabric” as used herein refers toa nonwoven fabric that has been bonded by applying heat and pressure tothe nonwoven fabric between two substantially smooth bonding surfaces. Afull-surface bonded nonwoven fabric is bonded over substantially 100% ofits outer surfaces by fiber-to-fiber bonds. The use of smooth bondingsurfaces results in each side of the full-surface bonded nonwoven fabricbeing substantially uniformly bonded. Full surface bonded nonwovenfabrics are described in co-pending U.S. Patent Application No.60/529,997 (DuPont Docket no. TK-3820), filed on even date herewith andincorporated herein by reference in its entirety.

FIG. 1 illustrates a schematic elevation view of a blister packageaccording to the present invention. Lidding component 1 is heat-sealedto a blister component comprising a plurality of cavities 2. The liddingand blister components are heat-sealed in the shoulder areas 3 thatseparate the individual cavities. The shoulder areas generally includeperforations (not shown) between the individual blisters or groups ofindividual blisters.

The blister component is formed from a forming web that comprises atleast one barrier layer, for example a polymeric film, coated polymericfilm, or metal foil. Forming webs suitable for forming the blistercomponent are known in the art. For example, the blister component canbe prepared by thermoforming cavities into a barrier film. Alternately,the blister component can be formed from a soft-tempered or ahard-tempered foil such as an aluminum foil layer. Films and foilssuitable for forming the blister component generally have a thicknessbetween about 5.0 mils (0.125 mm) and 15 mils (0.38 mm) forchild-resistant packaging. For example, a typical film thickness isabout 10 mils (0.25 mm). The blister component can be formed from amulti-layer sheet structure, for example a multi-layer film or afilm-foil laminate.

FIG. 2 a is a cross-sectional view of an embodiment of a liddingcomponent suitable for use in peel-open, tear-open, and peel off-pushthrough blister packages of the present invention. Nonwoven layer 5,which comprises at least one melt-spun continuous filament sheet orflash spun plexifilamentary sheet, is bonded to barrier layer 7 byintervening adhesive tie layer 6. Heat-seal layer 8 is adhered to thebarrier layer on the side of the barrier layer opposite the tie layer. Ablister package is formed by heat-sealing the lidding component to theblister component with heat-seal layer 8 facing the blister componentsuch that nonwoven layer 5 forms one of the outer surfaces of theblister package. Tie layer 6 can form a peelable seal (e.g. in a peeloff-push through package) or a non-peelable seal (e.g. in a peel-open ortear-open package) between the nonwoven layer and the barrier layer,depending on the desired method for opening the blister package. A sealor bond is considered non-peelable if the layers bonded by thenon-peelable seal are not readily opened by an adult by hand-peeling.Generally a seal having a peel strength between about 3 to 4 lb/in ispreferred for a peelable seal. Peel strengths less than about 3 lb/inare generally peeled too easily to be useful in child-resistantpackages. Seals having a peel strength greater than about 4 lb/inch aregenerally considered to be non-peelable or permanent seals. Peelstrength can be measured according to ASTM F 88-0, which is herebyincorporated by reference, using the unsupported method of clamping thesample described therein. Similarly, heat-seal layer 8 can form apeelable seal (e.g. in a peel-open package) or a non-peelable seal (e.g.in a peel off-push through or tear-open package) between the barrierlayer and the blister component. Examples of lidding constructionsaccording to FIG. 2 a include: (a) melt-spun continuous filamentnonwoven sheet/adhesive tie layer/metal foil/heat-seal layer, (b)melt-spun continuous filament nonwoven sheet/adhesive tie layer/barrierfilm (metalized or unmetalized, coated or uncoated)/heat-seal layer, and(c) flash spun plexifilamentary sheet/adhesive tie layer/barrier film(metalized or unmetalized, coated or uncoated)/heat-seal layer. Thebarrier film can be a film that is laminated to the nonwoven sheet orcan be a layer that is co-extruded with the adhesive tie layer onto thenonwoven sheet.

Barrier layers suitable for use in the lidding component shown in FIG. 2a include foil sheets such as aluminum foil and laminated structurescomprising a foil layer such as film-foil laminates, as well asmono-layer, multi-layer, and coated polymeric films, and metalizedpolymeric films.

Examples of other materials useful as either the barrier layers suitablefor use in the lidding component, or as the blister component includepoly(vinyl chloride) (PVC) used as a mono-layer film, PVC film coatedwith poly(vinylidene chloride) (PVdC), PVC film laminated withpoly(chlorotrifluoroethylene) (PCTFE) film such as Aclar® PCTFE filmavailable from Honeywell, Inc. (Morris Township, N.J.),cyclo-olefin-copolymer (COC) used as part of a laminated or co-extrudedstructure, cold-formable foil such as PVC/aluminum/nylon laminatedstructures, mono-layer aluminum foil, polypropylene (PP) used as amono-layer film, poly(ethylene terephthalate) (PET) used as a mono-layerfilm, and poly(ethylene terephthalate) copolymers that have beenmodified with 1,4-cyclohexanedimethanol, available from EastmanChemicals (Kingsport, Tenn.) as PETG copolymers, used as a mono-layerfilm.

In one embodiment the barrier layer comprises a polymeric filmcomprising a polymeric coating. For example, the barrier layer cancomprise a PVdC-coated polyester film such as PVdC-coated Mylar®polyester films (e.g. M30 and M34 films, available from DuPont TeijinFilms). In another embodiment, the barrier layer comprises a polymericfilm that has been coated with a ceramic material. Ceramic materialssuitable for coating polymeric films include oxides, nitrides, orcarbides of silicon, aluminum, magnesium, chromium, lanthanum, titanium,boron, zirconium, or mixtures thereof. Methods for depositing ceramiccoatings onto a substrate are known in the art, such as by depositionfrom the vapor or gaseous phase under vacuum onto a film layer inthicknesses of between about 5 to 500 nm. Suitable ceramic-coated filmsinclude films made of a thermoplastic material, such as polyolefin filmshaving a thickness of 23 to 100 μm or polyester films having a thicknessof 12 to 80 μm, that have been coated with at least one 5 to 500 nmthick layer of SiO_(x), where x is a number ranging from 1.1 to 2, orwith Al_(y)O_(z), where the ratio y/z is a number ranging from 0.2 to1.5. Alternately, the barrier layer can comprise a metalized filmprepared using processes known in the art such as vacuum deposition orsputter coating. In one embodiment, the barrier layer is a metalizedpolyester film, for example a poly(ethylene terephthalate) film, thathas a layer of aluminum metal coated thereon; preferably the metal layeris between about 10 Angstroms to 1000 Angstroms thick and the film ispreferably at least 12 microns thick. Metalized polyester films areknown in the art and include aluminum-coated polyester films such asMylar® MC2 aluminum-coated polyester film (available from DuPont TeijinFilms). When the barrier layer of the lidding component comprises aceramic-coated or a metalized polymeric film, the film can beceramic-coated or metalized on one or both sides. The polymeric film ispreferably ceramic-coated or metalized on one side thereof and thelidding is preferably constructed such that the metalized orceramic-coated side of the film contacts adhesive tie layer 6 to avoidflaking off of the metalized or ceramic layer onto the packaged materialwhen the package is opened. Metalized and ceramic-coated films generallyhave better barrier properties than unmetalized and uncoated films andtherefore are preferred when higher barrier is required than can beachieved with an un-metalized or uncoated film.

FIG. 2 b is a cross-sectional view of a second embodiment of a liddingcomponent suitable for use in peel-open and tear-open blister packagesof the present invention. The lidding component includes nonwoven layer5′ and heat-seal layer 8′. In this embodiment, the heat-seal layer isselected such that it is a barrier layer as well as being heat-sealable,thus eliminating the need for separate barrier and heat-seal layers. Thenonwoven layer comprises at least one melt-spun continuous filamentnonwoven sheet or at least one flash spun plexifilamentary sheet. Whenthe heat-sealable barrier layer is applied as a coating on the nonwovenlayer, it completely coats the nonwoven layer to provide the desiredbarrier properties in the blister package. For example, PVdC at a basisweight ranging from 5 g/m² to 120 g/m² coated on a nonwoven layerprovides sufficient barrier properties as well as functioning as aheat-seal layer. Depending on the selection of the heat-sealable barrierlayer and the blister component, the heat seal can be peelable ornon-peelable. When it is desired to form a peel-open package, theheat-sealable barrier layer and the blister component are selected suchthat the heat seal is peelable. When it is desired to form a tear-openpackage, the heat seal is preferably non-peelable. In one embodiment ofthe present invention according to FIG. 2 b, a tear-open package isformed using a PVdC blister component and a PVdC heat sealable barrierlayer (heat seal is non-peelable). In another embodiment of the presentinvention according to FIG. 2 b, a peel-open package is formed using aPVC blister component and a PVdC heat-sealable barrier layer, where thePVdC formulation is selected to form a peelable seal with the PVCblister. The lidding shown in FIG. 2 b optionally includes anon-peelable tie layer (not shown) between the nonwoven layer andheat-seal/barrier layer. For example the tie layer can be apolyester-based polyurethane composition such as Adcote® polyurethaneadhesives available from Rohm & Haas (Philadelphia, Pa.).

Melt-spun continuous filament nonwoven sheets suitable for use in thenonwoven layer in the lidding component include spunbond nonwoven websand composite nonwoven fabrics that comprise at least one spunbondnonwoven web. Spunbond webs suitable for use in the lidding component ofthe blister package of the present invention can be prepared usingspunbonding methods known in the art. Alternately, the melt-spuncontinuous filament nonwoven sheet can be formed from previouslycollected continuous filaments that are laid down on a collectingsurface, for example as in the process described in Davies et al. U.S.Pat. No. 3,595,731. Polymers suitable for forming the melt-spuncontinuous filament nonwoven sheet include polyesters such aspoly(ethylene terephthalate) and poly(1,3-propylene terephthalate),polyamides such as nylon 6,6 and nylon 6, polyolefins such aspolyethylene and polypropylene, and copolymers thereof.

The melt-spun continuous filaments of the continuous filament nonwovensheet can be spun from a single polymer or from a homogeneous orheterogeneous blend of two or more polymers. Alternately, the melt-spuncontinuous filament nonwoven sheet can comprise a multiple componentspunbond nonwoven web. Multiple component spunbond webs preferablycomprise a polymeric component that has a melting point that is lowerthan the melting point(s) of the other polymeric component(s) tofacilitate thermal bonding of the web. Examples of suitable multiplecomponent fiber cross-sections include bicomponent fibers such as thosehaving side-by-side or sheath-core cross-sections. In one embodiment ofthe present invention, the melt-spun continuous filament nonwoven sheetcomprises multiple component sheath-core spunbond fibers having asubstantially concentric cross-section wherein the melting point of thesheath component is at least 10° C., preferably at least 20° C., lessthan the melting point of the core component. Examples of suitablesheath/core polymer combinations are polyethylene/polyester such asfibers comprising a linear low density polyethylene sheath with apoly(ethylene terephthalate) core or a sheath comprising a blend ofLLDPE and HDPE with a PET core. In one embodiment, the melt-spuncontinuous filaments comprise a polyester copolymer sheath and apolyester core. For example, the sheath can comprise a poly(ethyleneterephthalate) copolymer and the core can comprise poly(ethyleneterephthalate). Poly(ethylene terephthalate) copolymers suitable for useas the sheath component include amorphous and semi-crystallinepoly(ethylene terephthalate) copolymers. For example, poly(ethyleneterephthalate) copolymers in which between about 5 and 30 mole percentbased on the diacid component is formed from di-methyl isophthalic acid,as well as poly(ethylene terephthalate) copolymers in which betweenabout 5 and 60 mole percent based on the glycol component is formed from1,4-cyclohexanedimethanol are suitable for use as the lowest-meltingcomponent in the multiple component fibers. Poly(ethylene terephthalate)copolymers that have been modified with 1,4-cyclohexanedimethanol areavailable from Eastman Chemicals (Kingsport, Tenn.) as PETG copolymers.Poly(ethylene terephthalate) copolymers that have been modified withdi-methyl isophthalic acid are available from E.I. du Pont de Nemoursand Company (Wilmington, Del.) as Crystar® polyester copolymers.

Composite nonwoven fabrics comprising a spunbond nonwoven web suitablefor use in the lidding component include spunbond-meltblown (SM)composite nonwoven fabrics, SMS composite nonwoven fabrics, andcomposite nonwoven fabrics that include other combinations of spunbondand/or meltblown nonwoven webs such as SMMS composite webs, etc. Themeltblown web(s) used to prepare the composite nonwoven fabrics can besingle component or multiple component meltblown web(s) and can beprepared using methods known in the art.

The nonwoven layer used in the lidding component can comprise a flashspun nonwoven sheet. Polymers suitable for forming flash spunplexifilamentary sheets useful in the lidding component of the blisterpackage of the present invention include polyethylene, polypropylene,and poly(ethylene terephthalate). One such flash spun plexifilamentarysheet is Tyvek® flash spun high density polyethylene, available fromE.I. du Pont de Nemours & Company (Wilmington, Del.).

A particularly suitable lidding component can be obtained bysmooth-surface thermal bonding of a nonwoven web can be achieved byheating the web between two smooth bonding surfaces to a temperaturesufficient to melt or soften the surfaces of the fibers on one or bothsides of the nonwoven web such that fiber-to-fiber thermal fusion bondsare formed at the fiber cross-over points on one or both surfaces of thenonwoven web, as disclosed in U.S. Ser. No. 60/529,997 (DuPont Docketno. TK-3820), filed on even date herewith and incorporated herein byreference in its entirety.

Thermal calendering processes using a variety of roll configurations areknown in the art. The nonwoven layer can be calendar bonded such thatone side of the nonwoven layer is thermally bonded, with the thermallybonded side forming one of the outer surfaces of the final blisterpackage. Alternately the nonwoven layer can be calendered such that bothsides of the nonwoven layer are thermally bonded. Examples of othercalendering processes suitable for bonding the nonwoven layer includethose disclosed in David, U.S. Pat. No. 3,532,589, Janis, U.S. Pat. No.5,972,147, and Lim et al., U.S. Pat. No. 5,308,691, which are eachincorporated herein by reference.

In one embodiment, the nonwoven layer comprises a full-surface bondedmelt-spun multiple component continuous filament nonwoven fabric orfull-surface bonded flash spun plexifilamentary sheet that has beenthermally bonded on both sides in a smooth-calendering process.Full-surface bonded melt-spun multiple component continuous filamentnonwoven fabrics have an improved combination of tensile and tearstrength for a given fabric thickness compared to comparablesmooth-calendered single component melt-spun nonwoven fabrics. Suitablefull-surface bonded melt-spun multiple component continuous filamentnonwoven fabrics include full-surface bonded bicomponent spunbond webssuch as a spunbond web comprising sheath/core fibers, wherein themelting point of the sheath is at least 10° C. less than the meltingpoint of the core, that has been smooth-calendered and bonded on bothsides. Suitable sheath components include polyester copolymers,poly(1,4-butylene terephthalate) (4GT), and poly(1,3-propyleneterephthalate) (3GT), and polyamides such as polycaprolactam (nylon 6).Suitable core components include poly(ethylene terephthalate) andpoly(hexamethylene adipamide) (nylon 6,6). For example, the full-surfacebonded bicomponent spunbond web can comprise bicomponent fibers having apolyester copolymer sheath and a poly(ethylene terephthalate) core.

The nonwoven layer preferably has a Spencer Puncture (measured accordingto ASTM D3420, modified for 9/16 in. diameter probe) of at least 0.98Joules, preferably at least 1.18 Joules, and more preferably at least1.97 Joules; a tensile strength (measured according to ASTM D5035) inboth the machine direction and cross-direction of at least 20 lb/in (35N/cm), preferably at least 22 lb/in (38.5 N/cm), and more preferably atleast 25 lb/in (43.8 N/cm); an elongation in both the machine directionand cross-direction of at least 15%, preferably at least 18%, and morepreferably at least 20%; and an Elmendorf Tear (measured according toASTM D1424) in both the machine direction and the cross-direction of atleast 0.075 lb (0.33 N), preferably at least 0.10 lb (0.45 N), and morepreferably at least 0.20 lb (0.89 N).

In one embodiment of the present invention the heat-seal layer comprisesa peelable sealant, thus providing a peel-open blister package. Whetheror not a particular heat-seal layer forms a peelable seal may depend onthe nature of the layers to which it is sealed (e.g. the blistercomponent and barrier layer for the embodiment shown in FIG. 2 a or theblister component and the nonwoven layer for embodiments shown in FIG. 2b). In a peel-open configuration, the package is opened by peeling themulti-layer lidding component away from the blister component, with thepeeling occurring between the heat-seal layer and the blister component.Peelable sealants suitable for use in the heat-seal layer of thepackages of the present invention include poly(vinylidene chloride), orsolvent-based sealants such as modified vinyl/acrylic sealants availablefrom Watson Rhenania (Pittsburgh, Pa.) such as JVHS-157-LT1 sealant, aswell as extrudable sealants, for example blends of polyolefin resinscomprising primarily ethylene vinyl acetate or ethylene methyl acrylatecopolymers, such as Appeel® resins, available from E.I. du Pont deNemours and Company (Wilmington, Del.). The heat-seal layer can beapplied to the barrier layer of the lidding component using methodsknown in the art including but not limited to roll coating, gravurecoating, spray coating, and extrusion coating. In a peel-open package, anon-peelable adhesive tie layer is preferably used to join the nonwovenlayer to the barrier layer so that the nonwoven and barrier layers arestrongly bonded together, allowing the multi-layer lidding to be cleanlypulled away from the blister component without delamination occurringbetween the nonwoven and barrier layers. Non-peelable adhesive tielayers suitable for use in lidding used in a peel-open package of thepresent invention include solvent-based two-component dry-bond adhesivecompositions such as polyester-based polyurethane adhesives, for exampleAdcote® polyurethane-based adhesives available from Rohm & Haas(Philadelphia, Pa.). In a dry-bond adhesive process, the adhesive isapplied to either the barrier layer or the nonwoven layer or both, andthe two layers are bonded together while the adhesive is “dry” orsubstantially free of solvent. If the starting adhesive compositioncomprises a solvent, it is dried prior to laminating the nonwoven layerto the barrier layer. Other adhesive compositions which provide anon-peelable tie layer include extrudable resins such as modifiedethylene vinyl acetate, ethylene vinyl acetate, and ethylene methylacrylate based resins, for example Bynel® and Nucrel® modified ethylenevinyl acetate and modified ethylene methyl acrylate resins, availablefrom E.I. du Pont de Nemours and Company (Wilmington, Del.).

In another embodiment of a blister package of the present invention, theblister package is a peel off-push through package wherein the outernonwoven layer is adhered to a frangible barrier layer by a peelable tielayer, and is peeled from the package to reveal the frangible barrierlayer through which the packaged material is pushed. A layer isconsidered to be frangible if a packaged material can be removed byrupturing the layer by applying pressure to the exterior of the blistercavity. Peeling may occur between the nonwoven layer and the adhesivetie layer or between the adhesive tie layer and the barrier layer. Theadhesive tie layer is preferably selected such that it remains adheredto the nonwoven layer and peels cleanly away from the barrier layer whenthe package is opened without tearing or otherwise rupturing the barrierlayer. That is, the adhesive tie layer preferably has a high adherenceto the nonwoven layer and a relatively lower adherence to the frangiblebarrier layer. If peeling occurs between the nonwoven layer and theadhesive tie layer, the adhesive tie layer should also be a frangiblelayer. For example, in a peel off-push through package comprising alidding component according to FIG. 2 a, the adhesive tie layer is apeelable layer such that the nonwoven layer can be peeled away from thebarrier layer of the lidding component, and wherein the combined barrierlayer/heat-seal layer (for peeling between the adhesive tie layer andthe barrier layer) or combined adhesive tie layer/barrierlayer/heat-seal layer (for peeling between the nonwoven layer and tielayer) is frangible. Examples of frangible barrier layers include metalfoils (e.g. aluminum foil), frangible polymeric films (e.g.biaxially-oriented poly(chlorotrifluoroethylene) films), frangiblemetalized polymeric films, and frangible ceramic-coated polymeric films.The frangible layer(s) are selected such that once the nonwoven layer(or combined nonwoven/adhesive tie layer) is peeled away from thepackage, the pharmaceutical or other packaged material can be pushedthrough the frangible layer(s). The adhesive tie layer can be extrudedor coated onto one or both of the nonwoven layer (e.g. Tyvek® flash spunhigh density polyethylene or melt-spun continuous filamentpolyester-based spunbond nonwoven) or frangible barrier layer and thenonwoven and barrier layer bonded together by the intermediate tielayer. Examples of suitable peelable tie layers include modifiedvinyl/acrylic compositions, such as JVHS-157-LT1 modified vinyl/acrylicadhesive available from Watson Rhenania (Pittsburgh, Pa.), or blends ofpolyolefin resins comprising primarily ethylene vinyl acetate orethylene methyl acrylate copolymers, such as Appeel® polyolefin resins,available from E.I. du Pont de Nemours and Company (Wilmington, Del.),and solvent-based modified acrylic pressure sensitive adhesive, such asAdcote L74X105 from Rohm & Haas (Philadelphia, Pa.). The heat-seal layerin a peel off-push through package is selected such that it forms anon-peelable seal between the blister component and the barrier layer inthe lidding. Examples of suitable permanent (non-peelable) sealantsinclude modified vinyl/acrylic compositions such as JVHS-157-2, or amodified polyester sealant such as GNS01-014, both available from WatsonRhenania (Pittsburgh, Pa.).

When a tear-open package is desired, the adhesive tie layer andheat-seal layer of FIGS. 2 a and 2 b are selected such that non-peelablebonds/seals are formed between the barrier layer and the blistercomponent and between the nonwoven layer and the barrier layer. Thisallows the package to be torn cleanly at a pre-formed notch in thepackage without peeling occurring between the various layers in themulti-layer lidding component.

The blister package of the present invention can be manufactured usingmethods known in the art. FIG. 3 illustrates a process that is suitablefor forming a blister package of the present invention. The blistercavities 10 are generally thermoformed into a forming web in-line justprior to filling the cavities with the material 12 to be packaged. Thelidding component 14 is unwound from roll 15 and brought into contactwith the formed and filled blister component such that the heat-seallayer of the lidding component contacts the blister component. Thelidding and blister components are heat sealed, typically using a heatedplaten 16 with or without a pattern. Generally, some areas are notsealed to provide a starting point for peeling off the lidding orselected layers of the lidding prior to removing the product. If thelidding component is not pre-printed, printing is generally done justbefore heat sealing (not shown). After heat-sealing, the individualblisters are generally perforated using methods known in the art (notshown) so that they can be removed at point of use. If the blisterpackage is a tear-open package, notches are formed in the individualblisters during the perforation step. The notches are preferablycontained internal to the package such that they are not exposed untilthe individual blister is removed at point of use. The notch can also beformed on one of the external edges of the blister package, howeverforming the notches internal to the package decreases the likelihoodthat a child will be able to tear open the package. Individual blisterpackages 18, which can comprise multiple blisters (as shown in FIG. 4)or a single blister, are then cut from the continuous sheet of sealedblisters. It is important that all materials maintain dimensionalstability through the blister package process due to the platenregistry, the print registry and the perforation registry.

The improved tear resistance provided by the continuous filament orplexifilamentary nonwoven layer in the lidding component of the packagesof the present invention provides peel off-push through and peel-openpackages wherein the lidding or nonwoven layer peels cleanly away fromthe package without tearing, whereas packages known in the art thatutilize paper-film-foil laminates often do not provide a clean peel,thus making it difficult for even an adult to open the package. Thepresent invention also reduces the number of processing steps requiredto manufacture the lidding compared to the prior art by replacing threelayers (paper-adhesive-film) with a single nonwoven layer. Although thetear resistance of the lidding component of the packages of the presentinvention is improved compared to prior art lidding materials, they canalso be used in tear-open packages wherein the tear is initiated by apre-formed notch.

Test Methods

In the description above the following test methods are employed todetermine various reported characteristics and properties. ASTM refersto the American Society for Testing and Materials.

Basis Weight is a measure of the mass per unit area of a fabric or sheetand is determined by ASTM D-3776, which is hereby incorporated byreference, and is reported in g/m².

Spencer Puncture is a measure of the ability of a substrate to resistpuncture by impact. Spencer puncture is measured for nonwoven fabricsand nonwoven/foil laminates using a bullet-shaped probe and isdetermined by ASTM D3420 (modified for 9/16 inch diameter probe) with apendulum capacity of 5.4 Joules, which is hereby incorporated byreference. It is reported in Joules. Spencer puncture was measured fornonwoven/film laminates according to ASTM D3420 using a pointed probe(modified for 9/16 inch diameter probe) with a pendulum capacity of 5.4Joules, and is reported in units of Joules.

Tensile Strength is a measure of the force required to break thematerial apart by pulling. For nonwoven fabrics and nonwoven/foillaminates, tensile strength is determined according to ASTM D5035, whichis hereby incorporated by reference, and is reported in units of lb/inor N/cm. For nonwoven/film laminates, tensile strength was measuredaccording to ASTM D882, which is hereby incorporated by reference, andis reported in units of psi.

Elongation is a measure of the extent a substrate with stretch before itbreaks and is determined by ASTM D5035, which is hereby incorporated byreference. It is reported in %.

Elmendorf Tear is a measure of the force required to propagate aninitiated tear from a cut or a nick. Elmendorf Tear is measured fornonwoven fabrics and nonwoven/foil laminates according to ASTM D1424,which is hereby incorporated by reference, and is reported in units oflb or N. Elmendorf Tear was measured for nonwoven/film laminatesaccording to ASTM 1922, and is reported in units of g/mm.

Graves Tear is a measure of the force required to initiate a tear and ismeasured according to ASTM D1004, which is hereby incorporated byreference, and is reported in units of Newtons.

Moisture Vapor Transmission rate (MVTR) was measured for Example 2 usingASTM F1249, which is hereby incorporated by reference, under theconditions of 38° C. and 100% Relative Humidity, and is reported inunits of g/m²/24 hr.

Oxygen Transmission Rate was measured for Example 2 using ASTM D3985,which is hereby incorporated by reference, at 23° C., 50% RH, and 100%oxygen, and is reported in units of cc/m²/24 hr.

EXAMPLE 1

This example demonstrates preparation of a blister package comprising alidding component according to FIG. 2 a, wherein the nonwoven layer wasa smooth-calendered full-surface bonded spunbond nonwoven web and thebarrier layer in the lidding was a metal foil.

A spunbond bicomponent nonwoven web was prepared in which the fiberswere continuous core/sheath fibers having a poly(ethylene terephthalate)(PET) core component and a co-polyester sheath component composed of 17mole percent modified di-methyl isophthalate PET copolymer.

The thermally calendered bicomponent spunbond web was then laminated toa 0.93 mil (0.024 mm) thick soft-tempered aluminum foil obtained fromAlcoa (Pittsburgh, Pa.) using Adcote 503 A/Cat F solvent-basedpoly(ethylene terephthalate)-based polyurethane permanent adhesive tielayer obtained from Rohm & Haas (Philadelphia, Pa.). An Inta-Rotodry-bond coater/laminator (Model ‘The Delaware’) was used to perform thelamination. The Adcote 503A/Cat F was mixed at a ratio of 62 percent byweight 503A, 3.5 percent by weight CatF, and 34.5 percent by weightmethyl ethyl ketone and the adhesive was applied using a reverse gravurecoating process. The bicomponent spunbond web was unwound from a primaryunwind and the adhesive was applied to the bicomponent spunbond webusing a reverse rotating gravure roll. Alternately, the adhesive can beapplied to the barrier layer. The gravure roll was engraved with a 35line per inch (13.8 line per cm) tri-helical pattern, where a continuoustriangular channel in the helical pattern circumvents the gravure roll.The machine speed was 65 ft/min (19.8 m/min). Typical line speeds usedin a reverse gravure coating process are usually between about 15 m/minto 305 m/min. The adhesive was applied at a dry coating weight of about8 g/m². An adhesive tie layer dry coating weight between about 3 g/m²and 10 g/m² is generally used, with a dry coating weight between about 4g/m² and 8 g/m² generally being preferred. A hot air impingement dryerwas used to dry the coated spunbond web to remove the solvent present inthe tie layer adhesive. Air heated to a temperature of 74° C. was forcedthrough a slotted nozzle assembly onto the adhesive-coated surface ofthe spunbond web evaporate the solvent.

After drying, the adhesive-coated spunbond nonwoven web layer waslaminated to the foil layer which was unwound from a roll and contactedwith the adhesive-coated side of the spunbond web in a nip formed by twocylindrical calendar rolls. One of the rolls was a rubber-covered rolland the second roll was a steel roll heated to 82° C. by internal waterheating. The nonwoven web contacted the heated steel roll in the nip andthe aluminum foil contacted the rubber-surfaced roll. The laminatedsubstrate was then rewound on the rewinder.

A solvent-based peelable heat seal layer was then applied to thealuminum foil side of the above-described spunbond nonwoven/aluminumfoil laminate using the reverse gravure coating process described above.The peelable heat seal composition used was a vinyl/acrylicsolvent-based sealant (JVHS-157-LT1, supplied by Watson-Rhenania,Pittsburgh, Pa.). The heat-seal coating was applied at 5.2 g/m² to thenonwoven/foil laminate. Generally, heat seal coatings applied at a drycoating weight of between about 4.8 to 5.6 g/m² are preferred. Afterapplying the sealant, the coated material was dried using the same hotair impingement dryer described above and an air temperature of 275° F.(135° C.) to remove the ethyl acetate solvent. After drying the laminatewas rewound on the rewinder. The multi-layer laminate can be useddirectly as a lidding component to prepare a blister package or furtherprocessed by printing on the nonwoven surface of the laminate prior toforming a blister package. Properties of the lidding component arecompared to a conventional paper-film-foil laminate that is used in theart as lidding in blister packages (CR-417, available from Hueck Foils(Wall, N.J.) in Table I below. The results demonstrate the significantimprovement in Spencer Puncture of the lidding of the present inventioncompared to the prior art lidding material. The puncture resistance ofthe laminate prepared in Example 1 was more than three times greaterthan the conventional lidding material. Blister packages preparedaccording to the present invention are expected to be much moredifficult for a child to chew through than conventional blisterpackages.

Blister packages were prepared according to the process shown in FIG. 3using a Klockner Medipak CP-2 form-fill-seal blister packaging machine.The forming web used to form the blister component was 10 mil (0.254 mm)Pentapharm M570/01 poly(vinyl chloride) film supplied by KlocknerPentaplast of America (Gordonsville, Va.). The platen used to heat sealthe lidding to the blister component was heated to a temperature of 180°C. to obtain a peel-open package. Numerous blister packages of thepresent invention were peeled open and each sample peeled cleanly, whichrepresents a significant improvement compared to blister packages knownin the art that utilize a paper/film/foil laminate in the lidding whichare prone to tearing during peeling.

TABLE 1 Properties of Lidding Component for Example 1 Example 1Conventional Lidding (nonwoven/foil) (paper/film/foil) Basis Weight(g/m²) 102.7 72.5 MD Tensile Strength 123.4 73.7 (N/cm) XD TensileStrength 56.6 55.5 (N/cm) MD Elongation (% at 0.117 0.097 3 lbs) XDElongation (% at 0.25 0.2 3 lbs) MD Elmendorf Tear (N) 1.16 1.11 XDElmendorf Tear (N) 0.98 0.89 Spencer Puncture (J) 1.34 0.39 Thickness(mm) 0.144 0.093

EXAMPLE 2

This example demonstrates preparation of a lidding component comprisinga flash spun plexifilamentary sheet and a metalized polyester filmsuitable for use in peel-open child-resistant blister packages.

A multi-layer laminated sheet was prepared using an extrusion laminationprocess with an Egan Coater/Laminator. First, a permanent adhesive tielayer was used to bond a layer of Tyvek® flash spun high densitypolyethylene sheet (Tyvek® 1073D, basis weight 74.6 g/m², available fromE.I. du Pont de Nemours and Company (Wilmington, Del.)) to a metalizedpoly(ethylene terephthalate) film (Mylar® 7100 metalized (aluminum) filmhaving a thickness of 12 microns, available from DuPont-Teijin Films).The permanent adhesive tie layer was Nucrel® 1214 ethylene methylacrylate resin. The Nucrel® 1214 resin was extruded between the nonwovenand film substrates by extruding onto the metalized side of the Mylar®polyester film at a thickness of 0.5 mil and subsequently contacting theextruded adhesive layer with the Tyvek® flash spun sheet. The Nucrel®copolymer was extruded using a single screw extruder (with an exittemperature of 450° F. (232° C.) through a feedblock with a 40 inch(101.6 cm) wide (internally deckled to 28 inches (71.1 cm)) Cloeren edgebead reduction die having 30 mil gap operated at 321° C. and abackpressure of 500 psig (3447 kPa) to form a 0.5 mil thick adhesivelayer. The air gap between the die exit and the nip (where the extrudatecontacts the metalized film) was 6 inches (15.2 cm) and the lead-in was−0.5 inch (−1.27 cm). The line speed was 399 ft/min (122 m/min). Theside of the metalized Mylar® 7100 film that contacted the Nucrel®adhesive was corona treated in-line at 3 kW prior to extruding theadhesive layer. The Tyvek® flash spun sheet was laminated to theadhesive-coated film and the assembly (Tyvek® nonwoven/permanent Nucrel®adhesive/metalized Mylar® film) was then passed over a chill roll havinga matte finish and operated at 10° C.

The above assembly was then extrusion coated with a layer of peelableheat-sealable sealant on the film side of the metalized Mylar® filmusing the Egan Coater/Laminator. The peelable sealant used was Appeel®20D745 ethylene methyl acrylate copolymer sealant. The film side of themetalized film was corona treated in-line at 3 kW prior to coating withthe sealant. The line speed was 299 ft/minute (91 m/min), the extruderexit temperature was 490° F. (254° C.), die width 40 in (101.6 cm)(internally deckled to 28 inches (71.1 cm)), air gap 6 inches (15.2 cm),lead in of −0.5 inch (−1.27 cm), a Teflon® fluoropolymer-coated pressureroll and a matte finish chill roll, with a nip pressure of 60 psi (414kPa). The laminate structure can be processed on a blister packagingmachine as the lidding component to form a child-resistant blisterpackage.

The properties of the lidding material are given in Table 2 below.

TABLE 2 Properties of Lidding Component Comprising Flash Spun Sheet andMetalized Film Property Example 2 Tensile Strength MD (psi) 8614 TensileStrength XD (psi) 9120 Graves Tear Strength MD (N) 33.82 Graves Tear XD(N) 34.35 Elmendorf Tear MD (g/mm) 1990 Elmendorf Tear XD (g/mm) 2225Spencer Puncture (J) 0.62 Oxygen Transmission Rate (cc/m²/24 hr) 40.967MVTR g/m²/24 hr 0.324

1. A blister package comprising a blister component having an innersurface and an outer surface and a multi-layer lidding component havingan inner surface and an outer surface, wherein selected portions of theinner surfaces of the blister and lidding components are adheredtogether to form at least one cavity therebetween, the blister componentcomprising a first barrier layer selected from the group consisting ofpolymeric films, coated polymeric films, metal foils, and film-foillaminates, and the lidding component comprising a second barrier layerand a nonwoven layer comprising at least one melt-spun continuousfilament nonwoven sheet.
 2. A blister package according to claim 1wherein the second barrier layer comprises a sheet layer selected fromthe group consisting of polymeric films, coated polymeric films,metalized polymeric films, and metal foils.
 3. A blister packageaccording to claim 2 wherein the lidding component further comprises anadhesive tie layer intermediate the second barrier layer and thenonwoven layer, and a heat-seal layer adhered to the side of the secondbarrier layer opposite the adhesive tie layer, such that the innersurface of the lidding component comprises the heat-seal layer and theouter surface of the lidding component comprises the nonwoven layer, andwherein the lidding and blister components are heat sealed to each otherto form a seal therebetween.
 4. A blister package according to claim 3wherein the heat-seal layer comprises a heat-sealable sealant selectedfrom the group consisting of poly(vinylidene chloride), vinyl/acryliccompositions, blends of polyolefin resins comprising ethylene vinylacetate copolymers, blends of polyolefin resins comprising ethylenemethyl acrylate copolymers, and polyester-based compositions.
 5. Ablister package according to claim 3 wherein the tie-layer comprises anadhesive composition selected from the group consisting of vinyl/acryliccompositions, blends of polyolefin resins comprising ethylene vinylacetate copolymers, blends of polyolefin resins comprising ethylenemethyl acrylate copolymers, ethylene vinyl acetate resins, ethylenemethyl acrylate resins, and polyester-based polyurethanes.
 6. A blisterpackage according to claim 3 wherein the seal between the heat-seallayer and the blister component is peelable such that the blisterpackage can be opened by peeling the lidding component from the blistercomponent.
 7. A blister package according to claim 6 wherein theheat-seal layer comprises a sealant selected from the group consistingof poly(vinylidene chloride), vinyl/acrylic compositions, blends ofpolyolefin resins comprising ethylene vinyl acetate copolymers, andblends of polyolefin resins comprising ethylene methyl acrylatecopolymers.
 8. A blister package according to claim 3 wherein the secondbarrier layer is frangible.
 9. A blister package according to claim 8wherein the adhesive tie layer is a peelable layer such that thecombined nonwoven and adhesive tie layers can be peeled away from thesecond barrier layer and a material packaged in the blister package canbe removed from the package after said peeling by pushing the packagedmaterial through the frangible barrier layer.
 10. A blister packageaccording to claim 9 wherein the adhesive tie layer comprises anadhesive composition selected from the group consisting of vinyl/acryliccompositions, blends of polyolefin resins comprising ethylene vinylacetate copolymers, and blends of polyolefin resins comprising ethylenemethyl acrylate copolymers.
 11. A blister package according to claim 9wherein the second barrier layer comprises a frangible sheet layerselected from the group consisting of frangible polymeric films andfrangible metal foils.
 12. A blister package according to claim 3wherein the second barrier layer comprises a metalized polymeric filmthat is metalized on one side thereof, and wherein the metalized side ofthe second barrier layer is adjacent the adhesive tie layer.
 13. Ablister package according to claim 3 wherein the second barrier layercomprises a polymeric film that is coated on one side thereof with aceramic material, and wherein the coated side of the second barrierlayer is adjacent the adhesive tie layer.
 14. A blister packageaccording to claim 12 wherein the metalized polymeric film comprises ametalized polyester film.
 15. A blister package according to claim 14wherein the metalized polyester film is a poly(ethylene terephthalate)film having a layer of aluminum metal deposited thereon.
 16. A blisterpackage according to claims 1, 9 or 14 wherein the nonwoven layercomprises a full-surface bonded multiple component spunbond web.
 17. Ablister package according to claim 13 wherein the ceramic material isselected from the group consisting of oxides, nitrides, and carbides ofsilicon, aluminum, magnesium, chromium, lanthanum, titanium, boron, orzirconium, and mixtures thereof.
 18. A blister package according toclaims 1 or 2 wherein the nonwoven layer comprises at least onemeltblown web sandwiched between first and second melt-spun continuousfilament nonwoven sheets.
 19. A blister package according to claim 18wherein the first and second melt-spun continuous filament nonwovensheets are multiple component spunbond nonwoven webs.
 20. A blisterpackage according to claim 19 wherein the at least one meltblown web isa multiple component meltblown web.
 21. A blister package according toclaim 20 wherein the first and second spunbond nonwoven webs comprisebicomponent sheath-core spunbond fibers wherein the melting point of thesheath component is lower than the melting point of the core componentby at least 10° C., and the at least one meltblown web comprisesbicomponent side-by-side meltblown fibers.
 22. A blister packageaccording to claim 18 wherein the nonwoven layer comprises a pluralityof meltblown webs sandwiched between the first and second melt-spuncontinuous filament nonwoven sheets.
 23. A blister package according toclaim 19 wherein the nonwoven layer is a thermally calendered nonwovenlayer.
 24. A blister package according to claim 23 wherein the nonwovenlayer is a full-surface bonded nonwoven layer.
 25. A blister packageaccording to claim 24 wherein the first and second multiple componentspunbond nonwoven webs comprise sheath-core spunbond fibers wherein thecore component comprises a polyester and the sheath component comprisesa polyester copolymer.
 26. A blister package according to claims 1 or 2wherein the at least one melt-spun continuous filament nonwoven sheetcomprises a spunbond nonwoven web.
 27. A blister package according toclaim 26 wherein the spunbond nonwoven web is a multiple componentspunbond nonwoven web.
 28. A blister package according to claim 27wherein the multiple component spunbond nonwoven web comprisesbicomponent spunbond fibers comprising a sheath component and a corecomponent, wherein the melting point of the sheath component is lowerthan the melting point of the core component by at least 10° C.
 29. Ablister package according to claim 28 wherein the core componentcomprises a polyester and the sheath component comprises a polyestercopolymer.
 30. A blister package according to claim 29 wherein the corecomponent comprises poly(ethylene terephthalate) and the polyestercopolymer is selected from the group consisting of poly(ethyleneterephthalate) copolymers that have been modified with1,4-cyclohexanedimethanol and poly(ethylene terephthalate) copolymersthat have been modified with di-methyl isophthalic acid.
 31. A blisterpackage according to any of claims 27-30 wherein the multiple componentspunbond nonwoven web is a thermally calendered multiple componentspunbond nonwoven web.
 32. A blister package according to claim 31wherein the thermally calendered multiple component spunbond nonwovenweb is a full-surface bonded spunbond nonwoven web.
 33. A blisterpackage according to claim 1 wherein the second barrier layer is aheat-sealable barrier layer adhered to the nonwoven layer, the innersurface of the lidding component comprises the heat-sealable barrierlayer, and the lidding and blister components are heat sealed togetherto form a seal therebetween.
 34. A blister package according to claim 33wherein the seal is a peelable seal such that the blister package can beopened by peeling the lidding component from the blister component. 35.A blister package according to claim 33 where in the seal is anon-peelable seal and the blister package further comprises at least onenotch located internal to the package or on an external edge of thepackage.
 36. A blister package according to claim 34 or 35 wherein theheat-sealable barrier layer comprises poly(vinylidene chloride).
 37. Ablister package according to claim 34 or 35 wherein the at least onemelt-spun continuous filament nonwoven sheet comprises a full-surfacebonded multiple component spunbond nonwoven web.
 38. A blister packagecomprising a blister component having an inner surface and an outersurface and a multi-layer lidding component having an inner surface andan outer surface, wherein selected portions of the inner surfaces of theblister and lidding components are bonded together to form at least onecavity therebetween, the blister component comprising a first barrierlayer selected from the group consisting of polymeric films, coatedpolymeric films, metal foils, and film-foil laminates, and the liddingcomponent comprising a flash spun plexifilamentary sheet and a secondbarrier layer comprising a sheet layer selected from the groupconsisting of polymeric films, coated polymeric films, and metalizedpolymeric films.
 39. A blister package according to claim 38 wherein thelidding component further comprises an adhesive tie layer intermediatethe second barrier layer and the flash spun plexifilamentary sheet, anda heat-seal layer adhered to the side of the second barrier layeropposite the adhesive tie layer, such that the inner surface of thelidding component comprises the heat-seal layer and the outer surface ofthe lidding component comprises the flash spun plexifilamentary sheet,and wherein the lidding and blister components are heat sealed to eachother to form a seal therebetween.
 40. A blister package according toclaim 39 wherein the heat-seal layer comprises a heat-sealable sealantselected from the group consisting of poly(vinylidene chloride),vinyl/acrylic compositions, blends of polyolefins comprising ethylenevinyl acetate copolymers, blends of polyolefin resins comprisingethylene methyl acrylate copolymers, and polyester-based compositions.41. A blister package according to claim 39 wherein the tie-layercomprises an adhesive composition selected from the group consisting ofvinyl/acrylic compositions, blends of polyolefin resins comprisingethylene vinyl acetate copolymers, blends of polyolefin resinscomprising ethylene methyl acrylate copolymers, modified ethylene vinylacetate resins, ethylene vinyl acetate resins, ethylene methyl acrylateresins, and polyester-based polyurethanes.
 42. A blister packageaccording to claim 39 wherein the seal between the heat-seal layer andthe blister component is peelable such that the blister package can beopened by peeling the lidding component from the blister component. 43.A blister package according to claim 41 wherein the heat-seal layercomprises a heat-sealable sealant selected from the group consisting ofpoly(vinylidene chloride), vinyl/acrylic compositions, blends ofpolyolefin resins comprising ethylene vinyl acetate copolymers, andblends of polyolefin resins comprising ethylene methyl acrylatecopolymers.
 44. A blister package according to claim 39 wherein thesecond barrier layer is frangible.
 45. A blister package according toclaim 44 wherein the adhesive tie layer is a peelable layer such thatthe combined flash spun plexifilamentary sheet and adhesive tie layercan be peeled away from the second barrier layer and a material packagedin the blister package can be removed from the package after saidpeeling by pushing the packaged material through the frangible barrierlayer.
 46. A blister package according to claim 45 wherein the adhesivetie layer comprises an adhesive composition selected from the groupconsisting of vinyl/acrylic compositions, blends of polyolefin resinscomprising ethylene vinyl acetate copolymers, and blends of polyolefinresins comprising ethylene methyl acrylate copolymers.
 47. A blisterpackage according to claim 45 wherein the second barrier layer comprisesa metalized polymeric film that is metalized on one side thereof, andwherein the metalized side of the second barrier layer is adjacent theadhesive tie layer.
 48. A blister package according to claim 45 whereinthe second barrier layer comprises a polymeric film that is coated onone side thereof with a ceramic material, and wherein the coated side ofthe second barrier layer is adjacent the adhesive tie layer.
 49. Ablister package according to claim 47 wherein the metalized polymericfilm comprises a metalized biaxially-oriented film.
 50. A blisterpackage according to claim 38 wherein the second barrier layer is heatsealable and is adhered to the flash spun plexifilamentary sheet, theinner surface of the lidding component comprises the heat-sealablebarrier layer, and the lidding and blister components are heat sealedtogether to form a seal therebetween.
 51. A blister package according toclaim 50 wherein seal is a peelable seal such that the blister packagecan be opened by peeling the lidding component from the blistercomponent.
 52. A blister package according to claim 50 wherein the sealis a non-peelable seal and the blister package further comprises atleast one notch located internal to the package or on an external edgeof the package.
 53. A blister package according to claim 51 or 52wherein the heat-sealable barrier layer comprises poly(vinylidenechloride).
 54. A blister package according to claim 38 or 39 wherein theflash spun plexifilamentary sheet is formed from at least one polymerselected from the group consisting of polyethylene, polypropylene, andpoly(ethylene terephthalate).
 55. A blister package according to claim54 wherein the second barrier layer comprises a sheet layer selectedfrom the group consisting of polyester films and polyester films havinga coating of aluminum metal deposited on at least one side thereof. 56.A blister package according to claim 55 wherein the second barrier layercomprises a polyester film comprising poly(ethylene terephthalate). 57.A blister package according to claim 1 wherein the nonwoven layer has aSpencer Puncture measured according to ASTM D3420 with a 9/16 inchdiameter probe and a pendulum capacity of 5.4 Joules of at least 0.98Joules, a tensile strength measured according to ASTM D5035 in both themachine direction and cross-direction of at least 35 N/cm, an elongationmeasured according to ASTM D5035 in both the machine direction andcross-direction of at least 15%, and an Elmendorf Tear measuredaccording to ASTM D1424 in both the machine direction and thecross-direction of at least 0.33 N.
 58. A blister package according toclaim 57 wherein the nonwoven layer has a Spencer Puncture of at least1.97 Joules, a tensile strength in both the machine and cross-directionof at least 43.8 N/cm, an elongation in both the machine direction andcross-direction of at least 20%, and an Elmendorf Tear of at least 0.89N.
 59. A blister package according to claim 57 or 58 wherein thenonwoven layer is a bicomponent spunbond web.